Shaft truing system

ABSTRACT

An apparatus for processing a drive shaft ( 11 ) for a vehicle, the drive shaft ( 11 ) having a longitudinal axis and first and second ends. There is provided a drive arrangement for coupling to the first end of the drive shaft and applying a rotatory force to the drive shaft ( 11 ). A second end support arrangement rotationally supports the drive shaft ( 11 ) at its second end. Also, a transaxial drive ( 35 ) for applying a transverse force in a direction transverse to the longitudinal axis of the drive shaft ( 11 ). The transaxial drive includes a transaxially displaceable roller arrangement for communicating with an outer surface of the drive shaft ( 11 ) in a region thereof intermediate of the drive arrangement and the support arrangement, via which the transverse force is applied. The transverse force has a magnitude sufficient to cause bending of the drive shaft ( 11 ) in the direction transverse to the longitudinal axis thereof as the drive shaft is rotated. In some embodiments, the transverse force has a magnitude sufficient to cause plastic deformation of the drive shaft ( 11 ) in the direction transverse to the longitudinal axis thereof as the drive shaft is rotated.

RELATIONSHIP TO OTHER APPLICATIONS

This application is a 35 USC 371 of PCT/US02/26567, filed Aug. 20, 2002.

This application claims the benefit of the filing date of U.S.Provisional Patent Application Ser. Nos. 60/313,741; 60/313,734; and60/313,739; all of which were filed on Aug. 20, 2001 in the names of thesame inventors as herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to methods and apparatus forstraightening shafts, and more particularly, to a system for truinglarge shafts, such as vehicle drive shafts.

2. Description of the Related Art

Vehicle drive shafts are large and tubular, and difficult to manufacturein a manner that they are rendered consistently true. Such shafts, amongother shaft products, are very sensitive to bends in their main shaftportions. These imperfections cause noise, vibration, and harshness(“NVH”) issues, and also make final correction balance of the productdifficult. One approach to achieving a correction to a vehicle driveshaft is to rotate the vehicle drive shaft while a human operatorobserves displacements resulting from irregularities. The human operatorwill apply a force upon the vehicle drive shaft in a direction thattends to compensate for the observed displacements. This not only is aslow process that is difficult to implement in a modern manufacturingenvironment, it requires significant skill on the part of the humanoperator. Clearly, the results will vary with the level of skill of thehuman operator.

The need for increased accuracy in the truing of vehicle drive shaftsresults in part from the significantly reduced noise emissions fromother modern vehicle components, particularly including the drive train.Modern vehicles are sufficiently quiet that drive shaft noise isbecoming an increasing portion of overall vehicle operating noise.

To date many tubular products have been manufactured with an excessiveamount of run out or bending imperfections. Manufacturers usuallyattempt to straighten the tubular product using primitive methods suchas a static press force applied between two “V” blocks directly on theshaft. The operator approximates how much force or tube deflection isrequired for straightening the assembly. This is done by rotating thetube between two “V” blocks and monitoring the run out of the assemblyon a dial indicator gauge. After establishing the maximum run out theoperator will position the tube on its high point, and force the tubeinto plastic deformation using a ram. The operator will then measureagain the amount of bend in the product and repeat the process as manytimes as needed to reduce the shaft bending into an acceptabletolerance. Bending in this case is defined as the deflection measuredbetween the three points identified by the “V” blocks, and the dialindicator. It should be noted that these points are not the same areasto which the vehicle would react to in actual operation. Many experts inthe field of drive shaft manufacturing feel the current straighteningoperations actually do more harm than good.

It is, therefore, an object of this invention to provide a systemwhereby a vehicle drive shaft can quickly and simply be trued.

It is another object of this invention to provide a system whereby avehicle drive shaft can accurately be trued without relying on the skillof a human operator.

The present invention significantly reduces the imperfections in atubular or cylindrical assembly related to bending. It is therefor wellsuited to drive shaft manufacturing. Most importantly the invention isalso designed to straighten the tubular assembly relative to a rotatingdatum. The rotating datum is referred to as the True Vehicle RunningCenter (TVRC) of the product. This process of truing is accomplished athigh rates of speed, which suits the operation well to mass production.

SUMMARY OF THE INVENTION

The foregoing and other objects are achieved by this invention whichprovides an apparatus for processing a drive shaft for a vehicle, thedrive shaft having a longitudinal axis and first and second ends. Inaccordance with the invention, there is provided a drive arrangement forcoupling to the first end of the drive shaft and applying a rotatoryforce to the drive shaft. A second end support arrangement rotationallysupports the drive shaft at its second end. Also, a transaxial drive forapplying a transverse force in a direction transverse to thelongitudinal axis of the drive shaft.

In one embodiment, the transaxial drive includes a transaxiallydisplaceable roller arrangement for communicating with an outer surfaceof the drive shaft in a region thereof intermediate of the drivearrangement and the support arrangement, via which the transverse forceis applied. The transverse force has a magnitude sufficient to causebending of the drive shaft in the direction transverse to thelongitudinal axis thereof as the drive shaft is rotated. In someembodiments, the transverse force has a magnitude sufficient to causeplastic deformation of the drive shaft in the direction transverse tothe longitudinal axis thereof as the drive shaft is rotated.

In a further embodiment, the second end support arrangement includesfirst and second rollers arranged to support rotatively the drive shaftin a direction counter to that of the transverse force. Also, the firstand second rollers of the second end support arrangement are eachprovided with radially extended central portions.

There is further provided a first end support arrangement forrotationally supporting the drive shaft at its first end. The first endsupport arrangement includes first and second rollers arranged tosupport rotatively the drive shaft in a direction counter to that of thetransverse force. The first and second rollers of the first end supportarrangement are each provided with radially extended central portions.Additionally, the first end support arrangement includes third andfourth rollers arranged to support rotatively the drive shaft in adirection opposite to that of the first and second rollers of the firstend support arrangement. Third and fourth rollers of the first endsupport arrangement are each provided with radially extended centralportions.

In a further embodiment, the transaxial drive includes an hydraulic ramfor applying an axial ram force and a linkage arrangement for deliveringthe axial ram force to the transaxially displaceable roller arrangement.The drive arrangement causes the drive shaft to be rotated at a rate ofrotation of approximately between 300 and 6000 rpm.

In some embodiments, the drive shaft has angularly displaceably coupledthereto a second drive shaft portion, and there is further provided asecond drive shaft portion support arrangement for supporting the seconddrive shaft portion rotatably in fixed axial relation to the drive shaftas the drive shaft is rotated. The fixed axial relation may, in someembodiments, be a substantially coaxial relationship. There is furtherprovided a universal coupler for coupling the second drive shaft portionto the drive shaft, which may be a Thomson shaft.

The second drive shaft portion support arrangement is configured topermit axial displacement of the second drive shaft portion in responseto non-trueness of the drive shaft and the application of the transverseforce in the direction transverse to the longitudinal axis of the driveshaft.

In accordance with a method aspect of the invention, there is provided amethod of improving the trueness of a drive shaft of a vehicle, thedrive shaft having a longitudinal axis and first and second ends, themethod having the steps of:

installing the drive shaft onto a support arrangement that supports thedrive shaft rotatively at its first and second ends;

rotating the drive shaft about its longitudinal axis;

applying a transaxial force to the drive shaft in a region intermediateof the first and second ends; and

releasing the transaxial force.

In one embodiment, there is provided the further step of applyingincludes the step of applying the transaxial force having a magnitudesufficient to bend the drive shaft as it is rotated. The step ofrotating the drive shaft about its longitudinal axis includes the stepof rotating the drive shaft at a rate of rotation of approximatelybetween 300 and 6000 rpm. There is also provided the further step ofsupporting in a second support arrangement a second drive shaft portionthat is angularly displaceably coupled to the drive shaft.

In other embodiments, there are provided the steps of:

permitting the second drive shaft portion to be displaced longitudinallyin the second support arrangement in response to non-trueness of thedrive shaft; and

permitting the second drive shaft portion to be displaced longitudinallyin the second support arrangement in response to the step of applying atransaxial force to the drive shaft.

In other embodiments, the step of applying a transaxial force to thedrive shaft includes the steps of:

actuating an hydraulic cylinder to produce an axial displacement of adisplacement element;

coupling the displacement element to a roller arrangement; and

engaging the roller arrangement to an outer surface of the drive shaftin a region of the drive shaft intermediate of the first and second endsthereof.

In accordance with a product aspect of the invention, there is provideda vehicle drive shaft product formed by the process of:

a. installing a hollow drive shaft tube onto a support arrangement thatsupports the hollow drive shaft tube rotatively at its first and secondends;

b. rotating the hollow drive shaft tube about its longitudinal axis;

c. applying a transaxial force to the hollow drive shaft tube in aregion intermediate of the first and second ends, the transaxial forcehaving a magnitude sufficient to bend the hollow drive shaft tube;

d. releasing the transaxial force; and

e. removing the hollow drive shaft tube from the support arrangement;

wherein the thus processed hollow drive shaft tube is the vehicle driveshaft product having a trueness characteristic within a range ofapproximately between ±0.004 inches.

The thus processed hollow drive shaft tube is the vehicle drive shaftproduct has a trueness characteristic within a range of approximatelybetween ±0.002 inches.

There is further provided the step of repeating steps a. through e. witha second hollow drive shaft tube to produce a second vehicle drive shaftproduct also having a trueness characteristic within a range ofapproximately between ±0.004 inches.

Preferably, The thus processed second hollow drive shaft tube is asecond vehicle drive shaft product having a trueness characteristicwithin a range of approximately between ±0.002 inches.

There is provided the further step of supporting in a second supportarrangement a second drive shaft portion that is angularly displaceablycoupled to the hollow drive shaft tube. The vehicle drive shaft productis the thus processed hollow drive shaft tube with the second driveshaft portion that is angularly displaceably coupled thereto.

In a further embodiment, there is provided the further step ofpermitting the second drive shaft portion to be displaced longitudinallyin the second support arrangement in response to non-trueness of thedrive shaft. Additionally, there is provided the further step ofpermitting the second drive shaft portion to be displaced longitudinallyin the second support arrangement in response to the step of applying atransaxial force to the hollow drive shaft tube.

BRIEF DESCRIPTION OF THE DRAWING

Comprehension of the invention is facilitated by reading the followingdetailed description, in conjunction with the annexed drawing, in which:

FIG. 1 is a simplified schematic representation of a front plan view ofan arrangement for truing a shaft constructed in accordance with theprinciples of the invention;

FIG. 2 is a simplified, partially cross sectional schematicrepresentation of a top plan view of a roller support arrangement shownat the left-hand portion of the arrangement of FIG. 1;

FIG. 3 is an end view from the left-hand side of the arrangement of FIG.1;

FIG. 4 is an end view from the right-hand side of the arrangement ofFIG. 1;

FIG. 5 is a top plan view of the arrangement of FIG. 1;

FIG. 6 is a simplified schematic representation of a side plan view ofthe ram portion of the arrangement of FIG. 1;

FIG. 7 is a simplified schematic representation of a front plan view ofa further arrangement for truing a shaft constructed in accordance withthe invention having a displaceable workpiece support arrangement forfacilitating installation, holding, and removal of a workpiece;

FIG. 8 is a simplified partially cross-sectional schematicrepresentation of a side plan view of a portion of the arrangement ofFIG. 7 for truing a shaft;

FIG. 9 is a simplified partially cross-sectional schematicrepresentation of a side plan view of a further portion of thearrangement of FIG. 7 for truing a shaft; and

FIG. 10 is a simplified schematic representation of a front plan view ofa further arrangement for truing a shaft constructed in accordance withthe invention.

DETAILED DESCRIPTION

FIG. 1 is a simplified schematic representation of a front plan view ofa truing arrangement 10 for truing a drive shaft 11 of the type that isused in the propulsion system of a motor vehicle, constructed inaccordance with the principles of the invention. In this embodiment,drive shaft 11 is supported at respective ends thereof by respectiveroller pairs (not completely shown in this figure) that are installedrotatably in respective ones of support beds 15 and 16 that aresupported on respective ones of bases 12 and 13. Support bed 15, in thisspecific illustrative embodiment of the invention, has associatedtherewith a further pair of support rollers (not completely shown inthis figure) that are installed rotatably in a securing support bed 18.In this specific illustrative embodiment of the invention, support bed15 and securing support bed 18 are coupled to one another by a pluralityof threaded posts 20.

FIG. 2 is a simplified, partially cross sectional schematicrepresentation of a top plan view of securing support bed 18 that isshown in the left-hand portion of FIG. 1. FIG. 2 shows securing supportbed 18 to have therein two rollers 22 and 23, roller 23 being showncross-sectionally. In one embodiment, all of the rollers in support beds15 and 16 are identical to rollers 22 and 23. Roller 22 isrepresentative in this specific illustrative embodiment of the inventionof all others of the stated rollers and is shown to have a radiallyextended central portion 24, which is the portion that communicates withdrive shaft 11.

Referring once again to FIG. 1, there is shown extending upward fromsupport bed 15 a portion of a roller 25 extending upwardly therefrom.Roller 25 is shown to have a radially extended central portion 26 thatis shown to communicate with drive shaft 11 on a datum line 28 (shown indashed format).

FIG. 3 is an end view from the left-hand side of the arrangement ofFIG. 1. Elements of structure that previously have been discussed aresimilarly designated. As shown in this figure, drive shaft 11 issupported and restrained by communication with the four rollers, aspreviously described. Each such roller is also shown to have a radiallyextended central portion, not all of which are specifically designated.

FIG. 4 is an end view from the right-hand side of the arrangement ofFIG. 1. Elements of structure that previously have been discussed aresimilarly designated. As shown in this figure, drive shaft 11 issupported by rollers 30 and 31. Each such roller is also shown in thisfigure to have an associated one of radially extended central portions32 and 33, as previously described.

Referring once again to FIG. 1, there is additionally shown a ramarrangement 35 installed on a base 36. Ram arrangement 35 is, in thisspecific illustrative embodiment of the invention, hydraulicallyactuated (hydraulic system not entirely shown) and is operated inresponse to actuation of an hydraulic cylinder 37 that is linked bylinks 38 and 39 to a press bar 40 via a restrained coupler 41. Press bar40 (also shown in FIG. 6) has coupled thereto a pair of roller supports43 and 44, each of which carries a pair of rollers (not entirely shownin this figure) that will be discussed in greater detail in connectionwith FIG. 6, below. Only rollers 46 and 47 are shown in this figure.Unlike the previously described support and restraining rollers, rollers46 and 47, as well as the other rollers of these roller pairs, see, forexample, roller 52 in FIG. 6, do not have a radially extended centralportion. The surfaces of these rollers that communicate with drive shaft11, in this specific illustrative embodiment of the invention, areslightly curved, as shown.

In operation, drive shaft 11 is rotated, as will be discussed below inconnection with the embodiment of FIG. 10. During such rotation,hydraulic cylinder 37 is actuated such that press bar 40, andconsequently the aforementioned roller pairs, of which rollers 46 and 52(FIG. 6) constitute one such pair, are urged downwardly in the directionof arrow 50. In response to the applied lateral force, drive shaft 11 isdeflected during the rotation. In this embodiment of the invention, thedrive shaft is deflected beyond the limit of restoration that would beeffective but for the rotation. Therefore, upon release of the lateralforce applied by ram arrangement 35, drive shaft 11 is restored to astraighter condition than before it being subjected to such a truingoperation.

FIG. 5 is a top plan view of truing arrangement 10, shown in FIG. 1.Elements of structure that previously have been discussed are similarlydesignated. Drive shaft 11 is shown to be supported, on its right handside, by rollers 30 and 31.

FIG. 6 is a simplified schematic representation of a side plan view ofthe ram portion of the arrangement of FIG. 1. It is to be understood,however, that any known suitable drive arrangement may be used in thepractice of the invention. Elements of structure that previously havebeen discussed are similarly designated. This figure shows that rollersupport 44 supports a pair of rollers 47 (previously mentioned) and 52.In this specific illustrative embodiment of the invention, both suchrollers are configured with a slightly curved surface that communicateswith drive shaft 11. It is additionally seen that restrained coupler 41is engaged with a track 54 via a further coupler 55 that is shown to beengaged on one side thereof to restrained coupler 41 and on its otherside to track 54. Such coupling ensures that rollers 47 and 52, as wellas roller 46 and its paired roller (neither of which is shown in thisfigure) travel exclusively in the directions of arrow 57.

FIG. 7 is a simplified schematic representation of a front plan view ofa truing arrangement 100 for truing a shaft constructed in accordancewith the invention. In this simplified arrangement, a base 110 hasinstalled thereon a shaft support 112 that, in this specificillustrative embodiment of the invention is provided with a pair ofpillow blocks 114 and 115. A shaft 120, which may in certain embodimentsbe a Thompson shaft, is rotatably engaged with each of the pillowblocks, and is coupled, by means of a coupler that is designatedgenerally in this figure as 122, to a vehicle drive shaft 125. Thevehicle drive shaft is provided at its distal end with a further couplerthat is designated generally in this figure as 127. The further coupleris coupled at its distal end to further rotatable structure (not shownin this figure), which in some embodiments of the present invention maybe similar to shaft support 112, pillow blocks 114 and 15, and shaft120.

Couplers 122 and 127 are configured to maintain a rotatory couplingirrespective of transaxial displacement of vehicle drive shaft 125resulting from it being either in a non-true condition or deflected inresponse to the application of a lateral force in the central regionthereof, as will be described below. In this specific illustrativeembodiment of the invention, coupler 122 has a part clamp 121 coupled tobar clamp 123 via a tool steel ball 124. Coupler 127 also is formed oftwo portions, a part clamp 128 and a lathe adapter 129, which locate andclamp on the shaft's datum centerline (not specifically identified inthis figure).

Once supported in a horizontal orientation, vehicle drive shaft 125 isrotated at approximately between 300 and 1500 rpm in this specificillustrative embodiment of the invention by the application of arotatory force by operation of structure that is not shown in thisfigure. Persons of skill in the art readily can configure structure forimparting rotation to vehicle drive shaft 125, and effect rates ofrotation without being limited to range of rate of rotation set forthherein.

There is additionally installed on base 110 a frame 130, which is inseveral respects similar, in this embodiment, to ram 35 describedhereinabove in connection with FIGS. 1 and 6. In the specificillustrative embodiment of FIG. 7, an hydraulic press 132, that will bedescribed in greater detail in connection with FIG. 8, is attached atits upper end to frame 130, and has installed on its lower end a pair ofroller mounts 134 and 135. Each such roller mount has installed thereona respectively associated one of roller pairs 137 and 138. In thisfigure, only one roller of each roller pair is shown. In a practicalembodiment of the invention, the rollers can be adjusted for width andoffset to accommodate shafts that have complex shapes, possibly due tocrush zones.

FIG. 8 is a simplified partially cross-sectional schematicrepresentation of a side plan view of a portion of truing arrangement100 showing roller pair 138 in communication with vehicle drive shaft125. Elements of structure that previously have been mentioned aresimilarly designated. In this specific illustrative embodiment of theinvention, the roller pairs apply a downward force on vehicle driveshaft 125 (in the direction of arrow 140), by operation of an actuator142 that is hydraulically operated in this embodiment. Actuator 142 iscoupled to one end of pivoted arm 144, which is coupled at its distalportion to a link 146. Thus, as actuator 142 is urged upwardly, link 146and roller mount 135 coupled thereto are urged downwardly, therebyexerting a lateral force on rotating vehicle drive shaft 125.

In operation, the downward force applied to vehicle drive shaft 125 isof a magnitude that, but for the rotation of the vehicle drive shaft,would cause a permanent deflection therein. That is, the force issufficient to bend the vehicle drive shaft into plastic deformation,beyond its static elastic limit. During such deflection, the ends ofvehicle drive shaft 125 are maintained in axial alignment by operationof couplers 122 and 127 that retain a fixed axial alignment. Uponeffecting a slow release of the lateral load while the shaft isrotating, the vehicle drive shaft is corrected to a true centerrotation. This process produces a near perfectly straight shaft relativeto the true vehicle rotating center (“TVRC”).

FIG. 9 is a simplified partially cross-sectional schematicrepresentation of a side plan view of a further portion of truingarrangement 100, showing pillow block 115 with shaft 120 installedtherein. The pillow blocks are constructed to withstand the lateral loadapplied to vehicle drive shaft 125 while same is rotated.

FIG. 10 is a simplified schematic front plan representation of a furtherarrangement 200 for truing a shaft constructed in accordance with theinvention. In operation, a human operator (not shown) inserts a driveshaft section 250 after the weld yokes 251 and 252 are attached. Driveshaft 250 may, in certain embodiments, be a section of a drive shaft ifthe assembly is a multi piece design. Chuck jaws 260 in a first clamphead 261 are designed to clamp at the True Vehicle Rotating Center(TVRC), which is defined as the imaginary line connecting the center ofthe two rotating datum. The operator then indexes a second clamp head265 to a position that allows it to clamp up to the TVRC of the distalend of drive shaft section 250 while air bags 270 and 271 arepressurized. The inflated air bags support the respective first andsecond clamp heads to the TVRC. It is understood, however, that forms ofsupport other than air bags can be used in the practice of theinvention.

During installation of drive shaft section 250 by the human operator,the drive shaft section is supported by a load support arrangement 280that is provided in this specific illustrative embodiment of theinvention with a pair of v-blocks 281 and 282 installed on a loadsupport 284. Load support 284 can be translated in the verticaldirection by operation of a cylinder 288 that may be actuated by anyknown mode of actuation, such as electrical, pneumatic, or hydraulic.Thus, for example, after the human operator or robotic conveyor depositsdrive shaft section 250 onto v-blocks 281 and 282, load support 284 israised to a position shown in phantom in the drawing and designated asload support 284A, whereby coupling of the drive shaft section to chucks260 and 265 is facilitated. At this point, in embodiments of theinvention where clamp support arrangements 290 and 291 are not in theform of rigidly mounted spindles, as will be discussed in further detailbelow, load support 284 is lowered and chucks 260 and 265 are releasedto droop by deflating respectively associated air bags 270 and 271.

In this specific illustrative embodiment of the invention, it is seenfrom FIG. 10 that first and second clamp heads 261 and 265 are coupledto respective ones of clamp support arrangements 290 and 291. Clampsupport arrangements 290 and 291 are each pivotally coupled torespective base portions 294 and 295 at respective pivot couplings 298and 299. Such pivoting freedom of motion permits the arrangement toaccommodate bends in drive shaft section 250, but it is to be understoodthat such is not needed in embodiments of the invention where clampsupport arrangements 290 and 291 are rigidly mounted.

It is to be noted that in this specific illustrative embodiment of theinvention clamp support arrangements 290 and 291 are permitted anaddition degree of freedom in the form of axial translation. This isrepresented in phantom in this figure as clamp support arrangements 290Aand 291A. Rollers 302 and 303 are axially displaceable, as shown inphantom in the figure at roller positions 302A and 303A. Also, in someembodiments the rollers can be adjusted for offset, in addition towidth, with respect to each other. It is to be understood, however, thatin certain embodiments of the invention, clamp support arrangements 290and 291 may be in the form of respective spindles that are rigidlymounted in a horizontal plane. In such an embodiment of the invention,chuck jaws 251 and 252 will permit articulation of the drive shaft asthe lateral load is applied.

Upon completing the installation described hereinabove, drive shaftsection 250 is rotated, as previously mentioned, and a ram 300 is thenlowered, illustratively hydraulically by actuation of cylinder 301,whereby rollers 302 and 303 are urged into axially transversecommunication with drive shaft section 250 to effect the plasticdeformation thereof, as previously described. During the truingoperation, one of base portions 294 and 295 is permitted to travelaxially, illustratively as a result of it being installed onaxially-directed rails (not specifically identified), in order toaccommodate variations in the effective length of drive shaft section250 as it is deformed axially in response to the application of thetransaxial force by rollers 302 and 303.

Although the invention has been described in terms of specificembodiments and applications, persons skilled in the art can, in lightof this teaching, generate additional embodiments without exceeding thescope or departing from the spirit of the invention claimed herein.Accordingly, it is to be understood that the drawing and description inthis disclosure are proffered to facilitate comprehension of theinvention, and should not be construed to limit the scope thereof.

1. An apparatus for processing a drive shaft for a vehicle, the driveshaft having a longitudinal axis and first and second ends, theapparatus comprising: a drive arrangement for coupling to the first endof the drive shaft and applying a rotatory force to the drive shaft; asecond end support arrangement for rotationally supporting the driveshaft at its second end; and a transaxial drive for applying atransverse force in a direction transverse to the longitudinal axis ofthe drive shaft; a first end support arrangement for rotatablysupporting the drive shaft at its first end, said first end supportarrangement including first and second rollers arranged to rotatablysupport the drive shaft in a direction counter to that of the transverseforce and third and fourth rollers arranged to rotatably support thedrive shaft in a direction opposite to that of said first and secondrollers; and said second end support arrangement including first andsecond rollers arranged to rotatably support the drive shaft at itssecond end in a direction counter to that of the transverse force. 2.The apparatus of claim 1, wherein said transaxial drive comprises atransaxially displaceable roller arrangement for communicating with anouter surface of the drive shaft in a region thereof intermediate ofsaid drive arrangement and said support arrangement, via which thetransverse force is applied.
 3. The apparatus of claim 2, wherein thetransverse force has a magnitude sufficient to cause bending of thedrive shaft in the direction transverse to the longitudinal axis thereofas the drive shaft is rotated.
 4. The apparatus of claim 2, wherein thetransverse force has a magnitude sufficient to cause plastic deformationof the drive shaft in the direction transverse to the longitudinal axisthereof as the drive shaft is rotated.
 5. The apparatus of claim 2,wherein said transaxial drive comprises: an hydraulic ram for applyingan axial ram force; and a linkage arrangement for delivering the axialram force to the transaxially displaceable roller arrangement.
 6. Theapparatus of claim 1, wherein said first and second rollers of saidsecond end support arrangement are each provided with radially extendedcentral portions.
 7. The apparatus of claim 1, wherein said first andsecond rollers of said first end support arrangement are each providedwith radially extended central portions.
 8. The apparatus of claim 1,wherein said third and fourth rollers of said first end supportarrangement are each provided with radially extended central portions.9. The apparatus of claim 1, wherein said drive arrangement causes thedrive shaft to be rotated at a rate of rotation of approximately between300 and 4500 rpm.
 10. The apparatus of claim 1, wherein the drive shafthas angularly displaceably coupled thereto a second drive shaft portion,and there is further provided a second drive shaft portion supportarrangement for supporting the second drive shaft portion rotatably infixed axial relation to the drive shaft as the drive shaft is rotated.11. The apparatus of claim 10, wherein the fixed axial relation is asubstantially coaxial relationship.
 12. The apparatus of claim 10,wherein there is further provided a universal coupler for coupling saidsecond drive shaft portion to the drive shaft.
 13. The apparatus ofclaim 10, wherein the second drive shaft portion comprises a Thomsonshaft.
 14. The apparatus of claim 10, wherein said second drive shaftportion support arrangement is configured to permit axial displacementof the second drive shaft portion in response to non-trueness of thedrive shaft and the application of the transverse force in the directiontransverse to the longitudinal axis of the drive shaft.
 15. A method ofimproving the trueness of a drive shaft of a vehicle, the drive shafthaving a longitudinal axis and first and second ends, the methodcomprising the steps of: installing the drive shaft onto a supportarrangement that supports the drive shaft rotatively at its first andsecond ends; rotating the drive shaft about its longitudinal axis;applying a transaxial force to the drive shaft in a region intermediateof the first and second providing a first end support arrangement forrotatably supporting the drive shaft at its first end including firstand second rollers arranged to rotatably support the drive shaft in adirection counter to that of the transverse force and third and fourthrollers arranged to rotatably support the drive shaft in a directionopposite to that of the first and second rollers; providing a second endsupport arrangement comprising first and second rollers arranged torotatably support the drive shaft at its second end in a directioncounter to the transverse force; and releasing the transaxial force. 16.The method of claim 15, wherein said step of applying comprises the stepof applying the transaxial force having a magnitude sufficient to bendthe drive shaft as it is rotated.
 17. The method of claim 15, whereinsaid step of rotating the drive shaft about its longitudinal axiscomprises the step of rotating the drive shaft at a rate of rotation ofapproximately between 300 and 4500 rpm.
 18. The method of claim 15,wherein there is provided the further step of supporting in a secondsupport arrangement a second drive shaft portion that is angularlydisplaceably coupled to the drive shaft.
 19. The method of claim 18,wherein there is provided the further step of permitting the seconddrive shaft portion to be displaced longitudinally in the second supportarrangement in response to non-trueness of the drive shaft.
 20. Themethod of claim 18, wherein there is provided the further step ofpermitting the second drive shaft portion to be displaced longitudinallyin the second support arrangement in response to said step of applying atransaxial force to the drive shaft.
 21. The method of claim 15, whereinsaid step of applying a transaxial force to the drive shaft comprisesthe steps of: actuating an hydraulic cylinder to produce an axialdisplacement of a displacement element; coupling the displacementelement to a roller arrangement; and engaging the roller arrangement toan outer surface of the drive shaft in a region of the drive shaftintermediate of the first and second ends thereof.